User guide

Enable output drive for each of the four external sync lines. Each integer represents a bitmask
selecting the trigger sources for that line. The bit mapping is described in section “Structure
ndigo trigger block” on page 34.
int auto trigger period
int auto trigger random exponent
Create a trigger either periodically or randomly. There are two parameters M = trigger period
and N = random exponent that result in a distance between triggers of
T = 1 + M + [1...2
N
] (3.1)
clock cycles.
0 ≤ M < 2
32
(3.2)
0 ≤ N < 32 (3.3)
There is no enable or reset as the usage of this trigger can be configured in the trigger block
channel source field.
int output mode
Defines the data representation in the output. Signed16 scales and INL-corrects the input. RAW
directly presents the ADC values.
#define NDIGO OUTPUT MODE SIGNED16 0
#define NDIGO OUTPUT MODE RAW 1
#define NDIGO OUTPUT MODE CUSTOM 2
#define NDIGO OUTPUT MODE CUSTOM INL 3
lut func custom lut
If the output mode is set to NDIGO OUTPUT MODE CUSTOM or
NDIGO OUTPUT MODE CUSTOM INL this function is used for mapping from ADC value to
output value. The driver will call this function with a value from -1 to +1 and the function must
return the corresponding signed 16 bit value that the board should return for an input voltage
relative to the full scale range.
typedef short (*lut func)(int channel, float x)
This can be used e.g. for custom INL, offset and gain correction that covers user front end
electronics. It can also invert the signal or correct the effect of logarithmic input amplifiers etc.
The LUT is applied on the board, thus using it does not cause any additional CPU load.
In the mode “NDIGO OUTPUT MODE CUSTOM INL” the on-board INL correction table is
applied before the user function, while “NDIGO OUTPUT MODE CUSTOM” does not perform
INL correction. In order to use the user lookup table functionality lut func must be set to a
pointer to the LUT-function.
3.4.2 Structure ndigo trigger
short threshold
Sets the threshold for the trigger block within the range of the ADC data of -32768 and +32768.
cronologic GmbH & Co. KG 33 Ndigo5G User Guide